Restarting database server or just the database

I am an application programmer. We have a SQL server 2012 instance that hosts many related databases(around 12 databases). The vendors did some changes to one of the database and the application and they want us to reboot the database server. I did some research and found out that rebooting a db server is always not a great option unless changes have been made in the server configuration. Is there a way to restart just that database? would that help?

I appreciate your help!

Thanks.